Aluminum containing polymeric propellant composition



United States Patent 3,429,754 ALUMINUM CONTAINING POLYMERIC PROPELLANTCOMPOSITION Gaetano F. DAlelio, South Bend, Ind., assignor, by directand mesne assignments, Cleveland, Ohio, a corporation of Delaware NoDrawing. Continuation of applications Ser. No. 751,106, July 28, 1958,Ser. No. 761,485, Sept. 17, 1958, and Ser. No. 762,226, Sept. 22, 1958.This application June 5, 1961, Ser. No. 125,891 US. Cl., 149-19 20Claims Int. Cl. C06b 1/00, 11/00; C06d /06 This invention relates topolymers containing aluminum and solid propellent fuel compositionscontaining such polymers. This application is a continuation ofapplicants copending applications Ser. Nos. 751,106, filed July 28,1958; 761,485, filed Sept. 17, 1958; and 362,226, filed Sept. 22, 1958,each application now abanoned.

Because of the high energy content of such compounds, aluminum compoundshaving aluminum to carbon bonds, such as aluminum alkyls, have beensuggested as fuel compositions. However, because of their tendency toignite spontaneously upon exposure to air, and the highly reactivenature of these compounds, the use of aluminum alkyls involvesconsiderable danger and necessitates various precautionary steps.Moreover, since they are liquids, their use as propellant fuels forrockets, mis siles, and related devices, has the drawbacks common toliquid fuels in that complicated containers and pumping devices arerequired, and the sloshing effect of the liquids in their containerscauses shifting of weight, which adversely affects directional control.

In accordance with the present invention, polymeric compounds havinghigh proportions of aluminum have been discovered which have more easilycontrolled flammability and reactivity than the aluminum alkyls whilestill retaining high energy content. Such polymeric materials can bemade in the solid state and thereby have the inherent advantages ofsolid fuels for propelling purposes.

It has surprisingly been found that compositions particularly effectiveas solid propellant fuels are prepared from 595% of solid or liquidoxidizing agent of the type used in solid propellant fuel compositions,such as potassium perchlorate, etc. and 955% of a polymer prepared frompolyalkenyl ethers having a plurality of unsaturated groups therein,e.g. ethylenic and acetylenic groups, and monoacetylenic ethers, such asdivinyl ether, etc., as described more fully hereinafter and aluminumhydrides, and/or their hydrocarbon derivatives, hereinafter referred togenerally as aluminum hydride compounds, which can be made to react insuch a manner as to produce polymers having aluminum in the polymerchain and in relatively high proportions.

The polymers produced accordingly have a plurality of repeating units ofthe formula in the polymer molecules wherein X is R or Y, Y is apolyvalent radical having at least one ether group therein, theremainder of said radical being hydrocarbon, having each of saidvalencies connected to a carbon atom in said hydrocarbon portion, andhaving at least 2 carbon atoms between each said valency and said ethergroup, and R represents hydrogen or a hydrocarbon radical, thehydrocarbon radical preferably containing no more than about 24 carbonatoms. Preferably there are more than 2 such repeating units in eachpolymer molecule, advantageously more than 4.

The polyunsaturated ethers that can be used in the to Dal Mon ResearchCo.,

practice of this invention include those having at least one etherlinkage between unsaturated groups. The hydrocarbon derivatives ofaluminum hydrides include those in which 1, 2, or more, including all ofthe hydrogen of an aluminum hydride, is replaced by one or morehydrocarbon radicals, such as aliphatic, aromatic, cycloaliphaticradicals, including combinations thereof, such as aralkyl, alkaryl,cycloalkyl-aryl, aryl-cycloalkyl radicals, etc. The aluminum hydridecompounds are reacted with the unsaturated ethers described herein(including those having substituents thereon which are nonreactive tosaid aluminum hydride compounds), having a plurality of ethylenic oracetylenic groups therein, or only one acetylenic group therein.

Typical aluminum hydride compounds that can be used in the practice ofthis invention include, but are not limited to, the following: aluminumhydride (AlH including its various polymeric forms (AlH aluminum alkyldihydrides, aluminum dialkyl hydrides, aluminum trialkyls, varioushydrocarbon derivatives of polymeric aluminum hydrides, etc. These canbe used as such, or in complex form with alkali metal hydrides, such aslithium hydrides and sodium hydrides, alkali metal alkyls, ethers,thioethers, tertiary amines, etc.

Specific examples of such compounds include, but are not restricted to,the following: dimethyl aluminum hydride, diethyl aluminum hydride,dipropyl aluminum hydride, dibutyl aluminum hydride, dipentyl aluminumhydride, diphenethyl aluminum hydride, dicyclohexyl aluminum hydride,methyl aluminum dihydride, ethyl aluminum dihydride, propyl aluminumdihydride, butyl aluminum dihydride, pentyl aluminum dihydride,phenethyl aluminum dihydride, 2-ethyl-hexyl aluminum dihydride,cyclohexyl aluminum dihydride, cyclopentyl aluminum dihydride,cyclohexylethyl aluminum dihydride, cyclopentylethyl aluminum dihydride,trimethyl aluminum, triethyl aluminum, tripropyl aluminum, tributylaluminum, triisobutyl aluminum, tripentyl aluminum, tri (2- ethyl-hexyl)aluminum, tri-phenethyl aluminum, tri-benzyl aluminum,tri-(2-decyl-tetradecyl) aluminum, triphenyl aluminum, tritolylaluminum, tetramethyl dialuane, trimethyl dialuane, pentamethyldialuane, symmetrical diethyl dialuane, tetraethyl dialuane, pentaethyldialuane, etc.

The polymeric products of this invention range from viscous oils tosolid thermoplastic or thermoset resins. Depending upon the particularstarting materials, modifiers, and polymerization conditions, thepolymers range in molecular Weight from about 300 to 100,000 and higher.These polymeric compositions are useful as high energy fuels, either asa supplement or as the main component, and are particularly useful inthe solid form for such purposes. Particularly useful infusible solidfuels can be made by incorporating a solid or liquid oxidizing agentinto the polymeric compositions of this invention while they are in aliquid or thermoplastic state, and then converting the polymer to acrosslinked infusible condition.

It is not intended that the invention be limited to any particulartheory, or to any particular formula. It is believed, however, that whena polyalkenyl ether is used having the formula R C=CR-ZCR=CR polymersobtained by the practice of this invention can be represented by theformula R- Al-Y- AIR: (t *wherein X is R or Y, and Y is a polyvalentradical derived from the polyalkenyl ether and having as many valenciesas there are aluminum atoms attached thereto. When derived fromdialkenyl ether, Y is a divalent radical. When derived from trialkenylether, Y can also be a trivalent radical. Also, in the above formulas, Rrepresents hydrogen or a hydrocarbon group; n is an integer greater than2, preferably greater than 4; and Z represents oxygen or a divalentgroup having hydrocarbon and ether oxygen therein with at least oneether linkage between said valencies. The hydrocarbon nucleus of R and Zcan have attached thereto substituents which are nonreactive toward thealuminum hydride compound used in the preparation of the polymer.However, additional ethylenic groups can also be attached to R and Zthrough ether linkages.

While it is believed that each aluminum becomes attached to one of thecarbon atoms of an ethylenic group, it is also possible that thealuminum migrates, during or after the reaction between the aluminumcompound and the polyalkenyl compound, and is attached to any othercarbon atom of the polyalkenyl compound that will give a more stablederivative. Thus, the aluminum may actually be attached to one of the Rgroups or to Z. For that reason Y is represented as a divalent radicalhaving the formula:

without pinpointing the carbon atoms to which the aluminum is actuallyattached.

Accordingly, the polymeric products are represented by the formula:

R' [;?1-(C2R3H ZC2R3H) inAlR2 When the aluminum becomes attached anddoes not migrate from the ethylenic group, the polymeric product canprobably be represented by the following formula:

When infusible polymers are obtained by the practice of this invention,the crosslinkages between linear polymer chains, such as representedabove when X is Y, can generally be represented by replacing an R groupfrom an aluminum atom in two different polymer molecules andsubstituting for two such R groups the divalent radical Y which can alsobe represented as:

When the aluminum hydride compound has no more than one hydrocarbongroup attached to each aluminum atom, such as aluminum hydride, methylaluminum dihydride, ethyl aluminum dihydride, propyl aluminum dihydride,symmetrical dimethyl dialuane, symmetrical di ethyl dialuane,1,2,3-trimethyl tr-ialuane, etc., and a polyunsaturated compound is usedwhich has two vinyl groups, it is believed that the polymerizationgenerally proceeds linearly, at least initially, as follows:

When an aluminum hydride compound which has two or more hydrocarbongroups on each aluminum atom or a linear polymer, such as above, is usedin which the R on the aluminum is a hydrocarbon group, at least some ofthe hydrocarbon groups are displaced by the dialkenyl compound. Forexample, when the three Rs on each aluminum atom are hydrocarbon groups,the polymer is generally believed to proceed linearly, at leastinitially, as follows:

In the preceding reaction when conditions permit, the hydrocarbon groupwhich is replaced by the polyalkenyl compound, generally escapes fromthe system as an olefin. In cases of closed systems, the buildup ofpressure, or reluctance of a radical such as phenyl toward olefinformation, can result in the attachment of the hydrocarbon group to thecarbon atom of the ethylenic group other than the one to which thealuminum is attached.

When infusible polymers are obtained by the practice of this invention,the crosslinkages between linear polymer chains, such as representedabove, can generally be represented by replacing an R group from analuminum atom in two different polymer molecules and substituting fortwo such R groups, the divalent radical Y.

Various modifications of polymeric materials can be made according tothe practice of this invention by adjusting the proportions of reactantsand the conditions under which the materials are made to react. Forexample, control of the proportions of reactants enables control overthe amount of crosslinking and the amount of polymer formation beforecrosslinking is effected. Thus, by increasing the proportion of thedialkenyl compound, a higher degree of conversion to polymer can beeffected before crosslinking begins. Likewise, the higher the ratio ofaluminum compound to polyalkenyl compound, the lower is the degree ofconversion before crosslinking takes place. The selectivity, type ofreaction, and product, can be controlled somewhat by selectingappropriate aluminum compounds, concentrations thereof, the polyalkenylcompound, and also by the use of certain amounts of monoalkenylcompounds. For example, since the hydrogen in these aluminum compoundsis more easily replaced than alkyl groups, it is possible thereby tocontrol somewhat the type and extent of reaction.

On the basis that functionality of the aluminum compound is 3, and thatof a dialkenyl compound is equivalent to 2, since each unsaturated groupacts as a monoalkylating agent, a rough estimate of the extent ofreaction can be calculated from the functionality equation P=2/F, whereP equals the extent of reaction and F is the func tionality of thesystem. Approximate values derived from such calculations are shown inthe following table:

Approximate Aluminum compound (moles) Dialkenyl extent of reactioncompound (moles) before crosslinking,

percent As indicated by these calculations, the higher the mole ratio ofthe aluminum compound to the dialkenyl compound, the sooner thecrosslinking is likely to occur as the reaction proceeds. When a mole oftrialkenyl compound, such as triallyl ether of glycerine, or trivinyloxybenzene is reacted with a mole of aluminum compound, AIR the value for Papproaches 67%, and when the tetra-allyl ether of penta-erythritol isused, the gellation value P approximates 57%.

When it is desired to prepare a thermoplastic resin according to thepractice of this invention, either for use as such or for mixture withother materials, or for intermediate treatment prior to conversion to aninfusible resin, it is advantageous to use an aluminum compound havingone hydrocarbon group per aluminum atom. However, thermoplastic resinscan also be prepared by controlling the reaction conditions whenunsubstituted aluminum hydrides are used, or when aluminum compounds areused having more than one hydrocarbon substituent per aluminum atom. Thepreparation of thermoplastic resins can also be facilitated by the useof limited amounts of monoalkenyl compounds which will replace some ofthe hydrogen on aluminum hydrides, and thereby retard crosslinking untildesired, at which time higher temperatures can be used to replace suchalkyl groups with the polyalkenyl compound. Thus, when it is desired tocontrol the molecular weight of a linear polymer, or to put terminalhydrocarbon groups on a polymer chain, this can be accomplished by usinga mono-olefin, such as ethylene, together with the polyalkenyl compound.The latter can also be effected by using a trisubstituted aluminum,alone or together with an unsubstituted or mono-substituted aluminumhydride.

Some control over the type and extent of reaction can be effected byusing aluminum hydride compounds having hydrocarbon groups of differentsizes. It is sometimes desirable, also, that the hydrocarbon group to bereplaced by the polyalkenyl compound is of a smaller size than thepolyalkenyl compound. This is particularly desirable where there is adisplaced hydrocarbon group escaping as a byproduct olefin. In suchcases a dialkenyl compound of higher boiling point than the resultantolefin permits escape of the olefin upon refluxing of the polyalkenylcompound or upon maintaining the reaction temperature below that atwhich the polyalkenyl compound vaporizes to an undesirable extent. Insome cases, particularly where the difference in volatility is notgreat, the olefin can be permitted to escape in a stream of thepolyalkenyl compound passing through the system, or in a stream of inertgas with additional polyalkenyl compound being fed to the system. Incases where the polyalkenyl compound has a higher vapor pressure thanany olefin that might be given off as byproduct, a closed system canadvantageously be used to favor the desired displacement.

The temperature conditions for the promotion of polymer formation inaccordance with the practice of this invention vary in accordance withthe reactivity of the reagents being used. When an aluminum hydride isbeing reacted with a polyalkenyl compound, a temperature in range of7080 C. is generally suitable. When aluminum hydride compoundscontaining both hydrogen and hydrocarbon groups are used, the reactioncan be controlled mainly to displace the hydrogen by keeping thetemperature below 100 C. When hydrocarbon groups are to be displacedfrom an aluminum hydride compound, a temperature of about 100120 C. ispreferred. Depending upon the decomposition temperature of theparticular reagent and the polymeric product, it is generallyadvantageous not to exceed a temperature of about 140 C. When a mixtureof an aluminum hydride and an aluminum hydride compound containinghydrocarbon groups is being used, it is generally desirable to maintainthe appropriate temperature until most of the hydrogen has beendisplaced and then to raise the temperature to that more suitable fordisplacement of the hydrocarbon group. In some cases the temperaturecontrol can be facilitated by the use of an inert solvent, such asheptane, octane, benzene, toluene, xylene, etc., whose boiling point isclose to the desired temperature.

The time required for polymer formation varies in accordance with thereactivity of the ethylenic groups in the polyalkenyl compound, the typeof group to be displaced in the aluminum hydride compound, thetemperature being used, and various other factors which would favor thereaction, such as the use of metal catalysts, such as nickel, cobalt,etc., the removal of the byproduct olefin, etc. With respect to the lastcondition, an increase in concentration of such byproduct olefinpromotes an equilibrium which competes with the progress of the polymerformation. Therefore, unless the olefin is permitted to escape, or it isabsorbed by addition, this tends to slow down the polymerization. Thepolymerization proceeds most rapidly with vinyl groups in thepolyalkenyl compound. Vinylidene groups also react rapidly when thesecond group attached to the doubly substituted carbon is relativelysmall. With larger groups in that position, longer reaction times andincreased temperatures, but still below decomposition temperature, aredesirable. Ethylenic groups having hydrocarbon groups attached to boththe alpha and the beta carbon atoms are still less reactive than theVinylidene groups, and require longer reaction time even at the morefavorable temperature conditions. The time will also vary in accordancewith the degree of polymerization required. While the more activereagents can give polymers in even less time, and while some of thehigher molecular weight products may require longer periods, many of thepolymeric products of this invention can be produced at moderatetemperatures in a matter of 12 to 48 hours. In some cases, such as, withthe nonreactive type of ethylenic groups, or when low temperatures, forexample as low as 50 C., are used, much longer reaction periods aredesirable. In such cases the reaction is continued until a solid productis obtained.

While the foregoing discussion uses polyalkenyl ethers for illustration,the same rules also apply to the reaction of ether compounds having oneacetylenic group therein, one acetylenic group and one or more ethylenicgroups, and also a plurality of acetylenic groups. In such cases, thesame conditions apply as described above with two aluminum atoms beingadded to the carbon atoms of the acetylene group instead of one aluminumbeing added as with an ethylenic group.

When a high proportion of aluminum is desired in the ultimate product,it is preferred that the unsaturated ether compound be of relatively lowmolecular weight, generally not over 200 or 300. Typical unsaturatedether compounds that can be used in the practice of this inventioninclude, but are not limited to, the following: divinyl ether, diallylether, vinyl allyl ether, propenyl vinyl ether, propenyl allyl ether,divinyl ether of resorcinol, divinyl ether of ethylene glycol, diallylether of ethylene glycol, divinyl ether of diethylene glycol,diisopropenyl ether, isopropenyl vinyl ether, isopropenyl allyl ether,isopropenyl butenyl ether, isopropenyl isoamylene ether, divinyloxybenzene, divinyloxy toluene, diallyl ether of resorcinol, diisobutenylether of hydroquinone, para-vinyloxy styrene, para allyloxy styrene,trivinyloxy benzene, triallyloxy benzene, tripropenyloxy benzene,vinylphenyl propargyl ether, vinyloxy-phenylacetylene, propargyl vinylether, dipropargyl ether, allyloxy-phenylacetylene, propargyl ethylether, propargyl phenyl ether, etc.

Also useful in the practice of this invention are polymer having ethergroups therein and a plurality of unsaturated groups, e.g. ethylenic andacetylenic groups. Typical polymeric starting materials are polymers ofthe above listed polyunsaturated ether compounds in which a substantialnumber of the unsaturated groups therein remain unpolymerized. Preferredpolymers of this type are linear polymers in which one of theunsaturated groups in the polyunsaturated ether monomer is polymerizedto form a linear carbon chain which has a number of unsaturated groupsattached to the linear carbon chain through the ether group of theoriginal monomer compound.

Polymers having pendant vinyl, Vinylidene or acetylenic groups, arepreferred in the practice of this invention. Typical polymers are thosehaving repeating units of the following types:

Typical mono-alkenyl modifiers that can be used in the practice of thisinvention include, but are not limited to,-

the following: ethylene, propylene, butene-l, butene-Z, hexene-l,hexene-2, t-butyl ethylene, 2,4,4-trimethyl-lpentene,2,4,4-trimethyl-pentene-2, cyclopentene, cyclohexene, styrene,1,1-diphenyl ethylene, vinyl cyclohexene, alpha-methyl-styrene, vinylnaphthalene, beta-methyl styrene, allyl benzene, allyl cyclohexane,decene-l, decene-2, decene-3, decene-4, decene-5, dodecene-l,dodecene-Z, tetradecene-l, hexadecene-l, cyclopentene, etc.

Various monoalkenyl ester compounds can also be used as modifiers, suchas, vinyl ether, vinyl propyl ether, allyl ethyl ether, allyl propylether, isopropenyl ethyl ether, isopropenyl propyl ether, etc.

Various methods of practicing the invention are illustrated by thefollowing examples. These examples are intended merely to illustrate theinvention and not in any sense to limit the manner in which theinvention can be practiced. The parts and percentages recited therein,and also in the specification, unless specifically provided otherwise,refer to parts by weight and percentages by weight. Unless indicatedotherwise, the terms polymer and polymeric are intended to includecopolymers and copolymeric.

EXAMPLE I A mixture of ten parts of triethyl aluminum dissolved in tenparts of heptane is added to three parts of divinyloxy benzene and isheated in an atmosphere of nitrogen to boil ofl the heptane. Thetemperature is raised to 100 C. and maintained there. Ethylene isgradually evolved from the reaction mixture. After heating for 48 hoursthe reaction mixture is a solid mass. The product is washed with heptaneto remove traces of unreacted triethyl aluminum. The washed product isstable in air in contrast to the aluminum alkyls which oxidize and burnin air. The product is ground with an equal weight of ammoniumperchlorate. The resultant mixture when ignited and tested according toknown tests for propellant thrust, shows excellent thrust properties.

EXAMPLE II Two parts of triethyl aluminum and ten parts of pvinyloxystyrene are mixed and heated in an atmosphere of nitrogen at 120 C. forhours. A solid, glasslike polymeric mass is formed. The product isground and washed with heptane and dried. The product does not melt at200 0, nor spontaneously combust at this temperature. In three differenttests, four parts of this polymer are ground individually with six partsof ammonium nitrate, lithium perchlorate, and potassium perchlorate,respectively. In each case the mixture, when ignited, burns very rapidlywith an intense white flame, and upon testing for thrust properties,according to known tests for such purpose, the product shows excellentthrust.

EXAMPLE III Various mixtures of triethyl aluminum and divinyloxy benzeneare heated under an atmosphere of nitrogen at a temperature of 120 C. Ineach case the mixture contains 11.4 parts of triethyl aluminum, and witheach experiment a progressively smaller amount of divinyloxy benzene, asfollows: 65, 49, 32, 16, 8, 5.5, and 4 parts, respectively. In each casea solid product is obtained, as in Example II, but the time required forthe formation of the cake is progressively decreased as lower amounts ofdivinyloxy benzene are used. In each case the product shows burningproperties similar to the product of Example II, and shows excellentthrust properties when burned as such with liquid oxygen, in accordancewith known tests for propellant thrust.

EXAMPLE IV The procedure of Example II is repeated, using 19.6 parts ofdiallyl ether, and 15.6 parts of tripropyl aluminum, and sealing themixture under vacuum in a glass tube. The resultant solid product showssimilar burning and thrust properties as for the products of Example II.

When the above procedure is repeated, using an equivalent amount ofdiallyl ether of ethylene glycol, in place of the diallyl ether, and anequivalent amount of triamyl aluminum in place of the tripropylaluminum, and raising the temperature at the end of the heating periodto about 135 C. for an additional 10 hours, similar results areobtained.

EXAMPLE V The procedure of Example II is repeated, with similar results,using in place of the divinyloxy benzene, an amount of divinyloxycyclohexane equivalent to the amount of divinyloxy benzene; in anothercase an equivalent amount of diallyloxy cyclohexane; and in the thirdcase an equivalent amount of p-vinyloxy cyclohexene.

EXAMPLE VI A mixture of 5 8 parts of ethyl aluminum dihydride and 190parts of diallyloxy benzene are heated under an atmosphere of nitrogenat a temperature of C. for five hours, and then at a temperature of C.for an additional fifteen hours. The resultant product, after washing,grinding, and mixing with perchlorate, as in Example II, shows excellentburning and thrust properties similar to those of the product of ExampleII.

EXAMPLE VII The procedure of the preceding example is repeated using anequivalent amount of diisopropenyloxy benzene in place of the diallyloxybenzene. Similar results are obtained.

EXAMPLE VIII Ten parts of aluminum diethyl hydride are heated in anatmosphere of nitrogen to 9095 C., and divinyl ether is passed in underreflux at a rate as fast as permitted by the reflux. After ten parts ofdivinyl ether have been added, and as fast as the reflux rate willpermit, the temperature is raised to -l30 C., and maintained within thatrange and under an atmosphere of nitrogen for an additional 24 hours.The resultant solid product, upon treatment and testing as in Example I,shows excellent burning and thrust properties.

EXAMPLE IX The procedure of the preceding example is repeated using anequivalent amount of ethyl aluminum dihydride. Similar results areobtained.

Similar results are also obtained when the procedure of Example VIII isrepeated using diisopropenyl ether in place of divinyl ether in onecase, and in another case using diisopropenyl ether and an equivalentamount of ethyl aluminum dihydride in place of the aluminum diethylhydride.

EXAMPLE X The following procedure is followed a number of times, usingin each case a different mixture as indicated in Table I below. Thenumber appearing before a'particular compound, in this table and insubsequent tables, indicates the number of parts by Weight of thatcompound used. In each case the mixture is maintained under anatmosphere of nitrogen at a temperature of l20-l30 C. for a periodlasting one hour after the reaction mixture has become a solid mass. Ineach case, the product is processed as in Example I, and upon testingexhibits excellent burning and thrust properties.

TABLE I Aluminum hydride compound Polyalkenyl compound Ininum.

22 1,7-divinyloxy-oetane.

25 'Iriethyl aluminum. 15 'Iripropyl aluminum. 18 Diisopropenyloxybenzene.

26 Triphenyl aluminum. 30 Tritolyl aluminum.

EXAMPLE XI TAB LE II Aluminum hydride compound 30 Styryl aluminumdihydride.

25 Distyryl aluminum hydride. 40 Diethyl aluminum hydride.

60 Ethyl aluminum hydride.

70 Symmetrical dipropyl dialuane. 60 Tetraethyl dialuane.

Polyalkenyl compound 18 Divlnyloxy benzene.

22 Divinyloxy naphthalene. 45 1,7-dlallyloxy octane.

90 Diallyloxy eyclohexane. 130 Divinyloxy benzene.

145 Divinyloxy oyclohexane.

EXAMPLE XII Various mixtures indicated in Table HI below are treatedaccording to the following procedure. The mixture is heated, in eachcase, under a blanket of nitrogen under reflux, and in accordance withthe corresponding increase in reflux temperature. The temperature isgradually increased to 7580 C. and maintained at that temperature forapproximately five hours. Then the temperature is gradually increased to120-125 C. and maintained in that range until the reaction mixture hasformed a solid mass, following which the temperature is raised to 130135C. for a period of two hours. The product is processed as in Example I,and, in each case, upon testing exhibits excellent burning and thrustproperties.

TABLE III Aluminum hydride compound Polyalkenyl compound 60 -I urane.115 Vinyloxy cyclohexene.

140 2-allyloxy-hexene-5.

100 Diallyl ether; 180 Dimethallyl ether.

EXAMPLE XIII To a flask equipped with a reflux condenser and nitrogeninlet, is added 0.5 part of divinyl benzene, 1.55 parts of divinyloxybenzene, and 10 parts of triisobutyl aluminum dissolved in 10 parts ofheptane. The resultant solution is heated under nitrogen for two days ata temperature of 60 C. At the end of this time, the reaction product isa solid, hard mass. This is broken up and ground with ammoniumperchlorate in a proportion of 3 parts of ammonium perchlorate per partof reaction product. The resultant mixture burns vigorously uponignition and shows excellent thrust properties.

EXAMPLE XIV The procedure of Example XIII is repeated, using 1.5 partsof divinyloxy benzene, 4 parts of styrene, 0.2 part of diethyl ether,and 5 parts of triisobutyl aluminum dissolved in 5 parts of heptane. Thereaction mixture is heated to 60 C. for three days. On the fourth day,the temperature is raised to 110 C., whereupon thickening of thereaction mixture occurs. Upon continued heating, a gel forms by thefifth day. B the end of the sixth day, a waxy, light yellow, solidproduct is obtained. By grinding with ammonium perchlorate in theproportion of three parts of ammonium perchlorate per part of reactionproduct, a mixture is obtained which burns vigorously upon ignition andshows excellent thrust properties.

10 EXAMPLE xv A mixture of 12 parts of triethyl aluminum and 24 parts ofB(CH CH 0CH=CH is heated under an atmosphere of methane at 120-125 C.for approximately 48 hours. An insoluble, infusible product is obtained,which is believed to have a plurality of repeating units of thestructure:

By using equivalent amounts of the corresponding dibutenyl magnesium anddibutenyl beryllium, respectively, in place of the tributenyl borane,and in each case repeating the preceding procedure, two solid productsare obtained which are believed to have a plurality of repeating units,in one case of:

EXAMPLE XVI A solution of 120 parts p-vinyloxy-phenyl acetylene in partsof cyclohexane is maintained under an atmosphere of nitrogen and at atemperature of 50-55 C. While a solution of 30 parts of aluminum hydridein 100 parts of ether, also under a blanket of nitrogen, is dropped intothe cyclohexane solution at such a rate that no more than a 5 rise intemperature occurs. When the temperature rises above 60 C., the aluminumhydride solution is cut oil or the rate of addition is reduced until thetemperature has subsided to the desired range. During this additionperiod, the ether is allowed to vaporize from the reaction mass. Afterall the solution has been added, the heating is continued for a periodof two hours, after which the temperature is raised to the solventreflux temperature for a period of 10 hours. Then the solvent isdistilled off and, upon testing, the resultant product shows excellentburning and thrust properties, particularly with potassium perchlorate.

EXAMPLE XVII A solution of 15 parts of tristyryl aluminum and 15 partsof a solid, soluble polymer of para-vinyloxy styrene in 100 parts oftoluene, is heated in an atmosphere of nitrogen at 50 C. for one hour.Then the temperature is raised to 70 C. for two hours, and thereafterrefluxed for five hours. The toluene is then distilled off and thereaction mixture heated at -130 C. for 24 hours. The solid product iswashed with heptane to extract traces of unconverted tributyl aluminum.The washed product is more stable in air than the ordinaryorgano-aluminum compounds which oxidize and burn in air. The resultantproduct is ground with an equal weight of ammonium perchlorate. Theresultant mixture, when ignited, burns very rapidly with an intensewhite flame, and when tested according to known tests for propellantthrust, shows excellent thrust properties, particularly with potassiumperchlorate.

EXAMPLE XVIII The procedure of Example XVII is repeated, using 16 partsof a solid, soluble polymer of p-allyloxy-styrene, in place of thevinyloxy-styrene. The product shows similar burning and thrustproperties.

EXAMPLE XIX The following procedure is repeated three times using 100parts of diallyl ether, 120 parts of divinyl benzenedivinyl ethercopolymer 80-20 mole ratio) and 160 parts p-vinyloxy-styrenerespectively. In each case the polyunsaturated polymer dissolved in 100parts of benzene, together with any catalyst or modifier, is maintainedunder an atmosphere of nitrogen at a temperature of 50-55 C. A solutionof 30 parts of aluminum hydride in 100 parts of ether is dropped intothe reaction mixture covered by a blanket of nitrogen, at such a ratethat no more than a percent rise in temperature occurs. When thetemperature rises above 60 C. the aluminum hydride solution supply iscut off or reduced until the temperature has subsided to the desiredrange. During this addition period, the ether is allowed to vaporizefrom the reaction mass. After all the solution has been added, theheating is continued for a period of two hours, after which thetemperature is raised to the solvent reflux temperature for a period often hours. Then the solvent is distilled off and heating continued at 90C. for an additional hours. The resultant product in each case showsexcellent burning and thrust properties.

EXAMPLE XX A solution of parts of ethyl aluminum dihydride, 150 parts ofp-allyloxy styrene, 10 parts of styrene and 150 parts of benzene isheated under an atmosphere of nitrogen at C. for one hour, then at C.for two hours, then refluxed for five hours, following which the benzeneis distilled off and the reaction mixture heated at C. for 48 hours.Excellent burning and thrust properties are exhibited when the productis tested, particularly when mixed with potassium perchlorate.

In accordance with the preceding, specific Y groups are illustratedbelow in the repeating unit given for polymers prepared in the variousexamples given above. For example the polymers of Examples I and IIIhave repeating units having the formula CzHs The polymer of Example IIhas a repeating unit having the formula -1]\l-C2H4C5H4O CzH4- Thepolymers of Example IV have repeating units respectively of the formulasA1o Hto 0 H,-

and

--A1-C Ha0 CHzCHsO CaHg-v JaHn The polymers of Example V have repeatingunits respectively of the formulas AIC2H4O CaHioO C 2H4- AlC H O CflHlBCa trand --A1C2H40CuHl0 The polymer of Example XVII has repeating unitsof the formulas CH2CH- 1 2 and The polymer of Example VI has repeatingunits of the formula The polymer of Example VIII has repeating units ofthe formula The polymer of Example XVI has repeating units of theformulas t hHt The polymerization described herein can be suspended atan early stage to give low-melting, solid polymers, or in some casesviscous oils, which can be stored as such and the polymerizationreaction continued at a subsequent time. In fact, the reaction can besuspended when the product comprises substantially a monomeric product,such as, for example, that derived from an aluminum hydride compound andvinyl ether, namely:

R A1CH CH OCH=CH RAl CH CH O CH=CH 2 or Al(CH CH OCH=-CH and thepolymerization completed later by the application of heat, or by theaddition of aluminum hydride compounds or other reagents, catalysts,modifiers, etc.

Various modifiers can be added to the compositions of this inventionafter the polymerization is completed, and in cases where the modifiersare nonreactive with the aluminum hydride compounds, can be added priorto the initiation of the polymerization, or at some intermediate stage.Hydrocarbon materials, such as various hydrocarbon resins, e.g.polystyrene, polyethylene, polypropylene, polybutenes, paraffins, etc.,can be added at any time. Certain other resins that might influence thereaction, or be reduced, or reacted upon by the aluminum hydridecompound, such as those containing ester, amide, or other functionalgroups, can be added after the polymers are formed. However, ifsuflicient aluminum hydride compound is added to compensate for thatused in such side reactions, such resins can often be added before orduring the reaction. Typical resins include, polyethers, such aspolymeric vinyl ethyl ether, polymeric vinyl butyl ether, etc.;polyesters, such as polyvinyl acetate, polyvinyl propionate, polyvinylbutyrate, polymethyl methacrylate, polymethyl acrylate, etc.; polyvinylacetal, polyvinyl butyral, etc., polyacrylonitrile, polyamides, such asnylon and polymeric caprolactam, etc.

Various other polyunsaturated compounds, or acetylenic compounds inaddition to those indicated above, can also be added, either beforeinitiation of the polymerization, at an intermediate stage, or at thecompletion of the polymerization reaction to modify the properties ofthe products. With regard to the esters, etc., reactive with thealuminum hydride compounds, the same comments apply as made above withrespect to resins having ester groups, etc. Such polyunsaturatedcompounds include: polyunsaturated hydrocarbons, polyunsaturated esters,polyunsaturated ether-esters, and various alkenyl boron compounds formedby the addition of boron alkyls to polyalkenyl hydrocarbon or ethercompounds, such as methyl-dibutenyl boron, tris (vinyloxyethyl)boron,etc., and the corresponding beryllium and magnesium derivatives.

Typical examples of such polyunsaturated compounds include, but are notrestricted to, the following: 1,3- butadiene, isoprene, 2,3-dimethylbutadiene, pentadiene- 1,3, hexadiene 2,4, octadiene 2,4, hexatriene1,3,5, 2- phenyl-butadiene, 1,3-pentadiene, hexadiene-1,5,2,4-dimethyl-pentadiene-2,4- vinyl cyclohexene,l-phe'nyl-pentadiene-l,3, divinyl cyclohexane, diallyl, 1,6-heptadiene,1,8- nonadiene, 1,8-decadiene, 2,9-dimethyl-2,8-decadiene, divinylcyclopentane, divinyl methyl cyclohexane, dipentenyl cyclohexane, allylcyclohexene, diallyl cyclohexene, divinyl cyclohexene,(beta-vinylalkyl)-furane, (beta-allylethyl)-furane, diallyl cyclohexane,diallyl cyclopentane, dibutenyl cyclohexane,l,7-diphenyl-heptadiene-1,6, 2,7-diphenyl-octadiene-l,7, divinylbenzene, trivinyl benzene, divinyl naphthalene, trivinyl naphthalene,divinyl diphenyl, trivinyl diphenyl, divinyl toluene, trivinyl toluene,divinyl xylene, divinyl anisole, divinyl ethyl benzene, divinylchlorobenzene, divinyl methylnaphthalene, divinyl ethylnaphthalene,divinyl methyldiphenyl, divinyl ethyldiphenyl, divinyl ethoxynaphthalene, divinyl chloronaphthalene, divinyl chlorodiphenyl, divinylethoxy diphenyl, vinyl isopropenyl benzene, vinyl isopropenylnaphthalene, vinyl isopropenyl diphenyl, vinyl isopropenyl toluene,vinyl isopropenyl anisole, vinyl isopropenyl chlorobenzene, vinylisopropenyl methoxy naphthalene, vinyl isopropenyl chloronaphthalene,vinyl isopropenyl methyl chloronaphthalene, vinyl isopropenylchlorodiphenyl, vinyl isopropenyl methoxy diphenyl, vinyl isobutenylbenzene, vinyl isobutenyl naphthalene, vinyl isobutenyl diphenyl, vinylallyl benzene, vinyl allyl naphthalene, vinyl allyl diphenyl, vinylallyl toluene, vinyl allyl anisole, vinyl allyl methylnaphthalene, vinylallyl chlorodiphenyl, diallyl benzene, triallyl diphenyl, diallyltoluene, diallyl xylene, diallyl chlorobenzene, diisopropenyl benzene,diisopropenyl naphthalene, diisopropenyl diphenyl, diisopropenyltoluene, diisopropenyl anisole, diisopropenyl methyl naphthalene,diisopropenyl chlorodiphenyl, dimethallyl benzene, dimethallylnaphthalene, dimethallyl diphenyl, bis-(alphaethyl-ethenyl)-benzene, bis(alpha-vinyl-ethyl)-benzene, bis (alpha vinyl ethyl) naphthalene,bis-(alpha-vinyl ethyl)-diphenyl, vinyl (alpha-vinyl-ethyl)-benzene,vinyl (alpha vinyl ethyl) naphthalene, vinyl (alphavinylethyl)-diphenyl, dipropenyl benzene, p-propenyl styrene,para-propenyl isopropenyl-benzene, dicrotyl benzene, dicrotylnaphthalene, dicrotyl diphenyl, dicrotyl anisole, dicrotyl xylene,bis-(4-vinyl-n-butyl)-benzene, bis-(S-isopropenyl-n-hexyl)-benzene,bis-(5 isopropenyl-n-hexyl)- diphenyl, bis (5 methyl-hepten 5yl)-benzene, bis-(5- methyl-nonen-6-yl)-diphenyl, bis(n-decen-S-yD-toluene, dicyclopentenyl naphthalene, di cyclohexenylbenzene, acetylene, allene, methyl acetylene, vinyl acetylene, phenylacetylene, phenylene diacetylene, naphthalene diacetylene, naphthylacetylene, cyclohexyl acetylene, allyl acrylate, allyl methacrylate,vinyl acrylate, vinyl methacrylate, isopropenyl acrylate, isopropenylmethacrylate, butenyl acrylate, butenyl methacrylate, vinyl crotonate,allyl crotonate, isopropenyl crotonate, propenyl crotonate, isobutenylcrotonate, ethylene glycol diacrylate, trimethylene glycol diacrylate,tetramethylene glycol diacrylate, pentamethylene glycol dimethacrylate,divinyl phthalate, diisopropenyl phthalate, dibutenyl phthalate, divinyldiphenyldicarboxylate, diallyl naphthalene-dicarboxylate, diallylitaconate, divinyl itaconate, divinyl maleate, diallyl maleate, diallylsuccinate, diisopropenyl succinate, dibutenyl succinate, divinylsuccinate, diallyl adipate, divinyl adipate, diallyl azelate, divinylazelate, diisopropenyl suberate, divinyl pimelate, diallyl glutarate,diisopropenyl glutarate, divinyl sebacate, diallyl sebacate, diallyljapanate, divinyl octadecanedioate, vinyl ll-acryloxy-undecanoate, allylll-methacryloxy undecanoate, isopropenyl 5-crotonoxy-caproate, vinyl4-acryloxy-caproate, vinyl ll-vinyloxy-undecanoate, allylll-allyloxy-undecanoate, vinyl llallyloxy-undecanoate, isopropenylll-isopropenyloxy-undecanoate, vinyl S-vinyloxy-caproate, vinylS-crotyloxycaproate, vinyl S-allyloxy-caproate, allylS-allyloxy-caproate, isopropenyl 5-isopropenyloxy-caproate,vinyloxytetramethylene acrylate, allyloxy-hexamethylene methacrylate,allyloxy-octamethylene crotonate, isopropenyloxyoctamethylene acrylate,crotyloxy-hexamethylene methacrylate, ethyl diallyl borane, propyldibutenyl borane, butyl dibutenyl borane, triallyl borane, tetra-allyldiborane, tri butenyl borane, tetrabutenyl diborane, dibutenylmagnesium, dibutenyl beryllium, etc.

In addition to the polyalkenyl type of boron, magnesium, and berylliumcompounds indicated above, it is desirable in some cases to addmonoalkenyl derivatives of such metals and to continue replacement ofthe remaining hydrogen or saturated hydrocarbon groups on the metal bymeans of the polyalkenyl compounds or by such compounds which havealready partially reacted with aluminum hydride compounds. By thesetechniques, both aluminum and other metals can be incorporated inpolymeric materials.

For many purposes, such as fuel, it is desirable to have a highconcentration of the aluminum polymeric units present in thecompositions. In such cases, the modifiers are used in minor amounts.However, in certain cases, it may be desirable to use the aluminumcomposition to modify or fortify the properties of other materials, inwhich case the aluminum derivatives are used in minor amounts.

As indicated above, the aluminum polymers of this invention areparticularly useful as solid fuels. They can be used as the main fuelcomponent or can be added to various types of other fuels to fortify orsupplement such fuels. For example, they can be used as additives togasoline and other motor fuels, to kerosene and other materials used forturbojet engines and jet engines, and can be added to liquid and solidpropellant fuels used for rockets, missiles, etc. However, thesepolymeric compositions are particularly useful as the main fuelcomponent in solid propellant fuels used for rockets and relateddevices. In such latter cases, it is advantageous to convert the fuel toan infusible form. If modifiers, or auxiliary agents, are to be added,this can be effected before conversion to infusibility. Depending on theparticular manner in which the fuel is to be used, it can be insolution, powder, rod, cylinder, or whatever other shape is convenient.

While such products should be made and stored under inert atmospheres,it is surprising that considerable amounts of oxidizing agents can beincorporated into these polymeric compositions and can be stored ininert atmospheres without danger of premature ignition or explosion.

After the desired amount of oxidizing agent has been incorporated intothe polymeric composition it can be converted to an infusible form byvarious means including the addition of more aluminum hydride compoundsor the addition of catalyst to catalyze further aluminumethylenicaddition, the application of moderate heating for similar addition, oreffecting crosslinking through the unsaturated groups themselves by heatalone, or by the addition of azo or other free radical-generatingcatalysts, or by any other means of crosslinking.

Oxidizing agents which can be incorporated in the resin for the ultimatepurpose of supporting combustion of the resin and which can beincorporated in accordance with safety conditions determined by theirreactivity, include: the solid and liquid perchloryl aryl compounds ofthe formula Ar-ClO such as perchloryl benzene, perchloryl toluene, etc.,various perchlorates, nitrates, oxides, persulates, and perborates ofmetals and ammonia, such as ammonium perchlorate, potassium perchlorate,sodium perchlorate, ammonium nitrate, potassium nitrate, sodium nitrate,potassium permanganate, potassium chlorate, manganese dioxide, potassiumiodate, potassium dichromate, chloric acid, perchloric acid, ammoniumpersulfate, ammonium dichromate, ammonium iodate, aluminum nitrate,barium chlorate, barium perchlorate, barium permanganate, lithiumperchlorate, lithium dichromate, lithium permanganate, etc.

Some of these oxidizing agents are not self-sustaining oxidizing agents,and can be used when free oxygen, or compositions such as perchlorylfluoride, highly concentrated hydrogen peroxide, etc., which generateoxygen in situ, are passed in surface contact with the fuel. The liquidoxidizing agents can be incorporated with precautions to assure uniformdistribution through the polymer mass and to avoid ignition or explosiveconditions during preparation and use of the fuel. It is desirable thatthe products from reaction of the oxidizing agent and the resin aregaseous in their normal state so that the energy developed in the systemwill not be robbed of energy to convert them to the gaseous state.

It is generally desirable that the fuel be molded in the shape in whichit is ultimately to be used before the composition is converted to aninfusible state. In fact, the fuel can even be cast or molded as oneentire unit which will comprise the entire fuel load for one rocket andcan be substantially as long as the rocket if desired. Therefore, thesize is limited only by the size of the rocket in which it is to beused.

It is possible to make the fuel in other shapes than indicated above andhave the fuel machined to give the desired shape. For example,cylindrical shapes are generally desirable with an opening runningthrough the cylinder along its linear axis. If desired, there can be aplurality of such openings running through the length of the mass sothat more than one oxidizing stream can function simultaneously.However, various other shapes can be used, such as blocks havingrectangular or square cross sections with one or more openings runningalong the linear axis of the block.

While the aforementioned shapes are preferred, it is also possible touse smaller units or shapes made by the practice of this invention, andthen to assemble them in a space or container advantageously in such amanner that one or more open linear paths are left through the assembledmass so that the oxidizing gas and/or the combustion gases can be passedtherethrough. For example, the fuel can be in the shape of discs with anopening in the center, or in half or quarter discs, or even withrectangular, square, or various other cross-sections so that uponassembly, one or more openings for the oxidizing gas are formed throughthe assembled mass. A cylindrical mass can be made of a number ofconcentric cylinders for which the outer diameter of one is slightlyless than the diameter of the inside linear opening of another so thatthe assembled cylindrical rnass actually comprises a number ofcylindrical sleeves which fit over one another. The axial opening of theone having the 16 smallest diameter would be the linear axis Opening ofthe assembled mass.

In addition to the foregoing, the resin-oxidizing agent composition canbe made in various other shapes, depending on the manner in which it isultimately to be used. As a further example, it can be shaped as a solidrod, in which case the burning surface will be the outer surface of therod or cylinder. The outer surface of the rod can be ignited and if asupplementary oxidizing fluid is used, this can be directed against suchouter surface of the rod. If desired, the rod can be advanced through anopening in accordance with the desired rate at which the surface is tobe exposed to a supplementary oxidizing fluid. The composition can alsobe shaped in the form of granules, pellets, etc., where it is desired tomodify the surface area that is to be exposed for combustion. Suchgranules can be used as such, or can be adhered to metal surfaces inaccordance with the present known art in the use of solid propellantfuel in granular form.

When the oxidizing agent to be added is a solid, it is desirably in fineparticle size so as to permit substantially uniform distributionthroughout the mass. The oxidizing composition which is to be passed insurface contact with the fuel is of the type generally used presently,such as pure or highly concentrated oxygen. The upper limit in theamount of oxidizing agent to be used is determined by the concentrationthat can safely be used under the conditions ultimately existing in thefuel zone of the rocket, or by that excess over the stoichiometricamount required for complete combustion of the fuel, whichever limit isreached first, Obviously, the safety limit will vary according to thetype of auxiliary oxidizing agent used. The type of fuel base materialused together with its heat capacity and heat transmission properties,the temperature which will exist in the preparation and use of the fuel,etc.

Since the fuel composition of this invention can be used according tovarious methods, varying from the use of a substantial amount ofsupplemental oxidizing fluid to that in which the combustion isself-sustained by the oxidizing compound contained in the fuel, theminimum amount of such oxidizing agent contained in the fuel will dependon the manner in which the fuel is to be used. When the combustion is tobe maintained partly by an oxidizing agent in the fuel and partly by theoxidizing agent pumped through the opening, then obviously thesupplemental effect of one agent toward the other will depend on theparticular material being used as the oxidizing agent in the fuel and onthe particular oxidizing fluid being fed through the opening.

Moreover, in each case the relative amounts cannot be determined on aweight basis but must be determined on the basis of the amount of oxygenavailable in the particular oxidizing agent used to support thecombustion. This depends on the oxygen content of the oxidizing agentand the percent of that oxygen that is liberated for oxidizing purposesupon decomposition of the oxidizing agent. Furthermore, this dependssomewhat on the efficiency with which its is desired to consume thefuel. For example, it might be desirable to have a considerable excessof oxidizing agent so as to consume the fuel more completely, eventhough it might mean an inefficient use of the oxidizing agent. Again,it is permissible to use the fuel with a low efliciency for use ofB.t.u. content, then it may be desirable to use a smaller amount ofoxidizing agent.

The amount of oxidizing agent inbedded in the fuel itself can be furtherdecreased when a supplemental oxidizing fluid is being pumped intocontact with the fuel. Obviously, therefore, the proportion of oxidizingagent imbedded in the fuel base material can vary from 5 percent toapproximately percent depending on the various factors involved, such asthe efliciency desired, the method and convenience of operation, and thematerials being used. Generally, when an oxidizing agent is imbedded inthe base material, it is advantageous to use from about 5 17 percent to95 percent, preferably about 20 percent to about 75 percent based on thecombined weight of oxidizing agent, base material, and any crosslinkingmodifier that is used.

When an oxidizing agent is used in the fuel base material of the typeand in the amount that will be self-sustaining in the combustion of thefuel base material, there will be no need to use an oxidizing fluid onthe surface of the fuel. In such cases, the combustion of the fuel isinitiated by igniting itby various means presently used for thatpurpose, such as a mixture of hydrazine, or unsymmetrical dimethylhydrazine, and nitric acid, or by triethyl aluminum and oxygen, or by atorch, or by an electrical ignition system. When the oxidizing agent isnot present in self-sustaining amount, liquid oxygen or an efficient,oxidizing compound such as perchloryl fluoride (FClO can be pumped intocontact with the surface of the fuel to supply the oxygen forcombustion. In some cases highly concentrated hydrogen peroxide, such as98 percent hydrogen peroxide can be used to supply oxygen forcombustion.

When a self-sustaining oxidizing agent is distributed throughout thefuel, the desirable amount can be determined by calculating thestoichiometric equivalent required for combustion of the fuel, andadjusting the calculation by subtracting, where less than 100 percent;efficiency is satisfactory, or adding, where desired, an excess tocompensate for the lack of 100 percent efliciency in the actualcombustion. Since the conditions of operation do not permit the time andtype of mixing which give 100 percent efficiency, where other factorspermit, it is sometimes desirable to have an excess of oxidizing agentwhich will give 50 percent, or even as high as 100 percent more than thestoichiometric amount of oxygen. When it is permissible or desirable tosacrifice some of the efiiciency of the B.t.u. content of the fuel, thestoichiometric amount or even less than that amount of the oxidizingagent can be used, depending on the fuel efficiency desired.

The oxidizing agent and/or modifier can be introduced or suspended inthe solid fuel in any convenient or appropriate manner. The mixture canbe effected mechanically as on mixing mils, on a Banbury mixer, anysingle or double worm extruder, or by rotation of the mold when thematerial is being cast from a liquid state. When; a solid is to beadded, the thermoplastic material can desirably be softened by theaddition of a softening agent, or, as indicated above, by the modifieritself. Such compounded mixtures can then be extruded, or otherwiseshaped into the desired form and then polymerized to infusibility. Insome cases, depending on the particle size of the solid oxidizing agentand the amount of void space between particles, the polymer in liquidstate, or the monomer from which it is to be prepared, together with apolymerization catalyst of the peroxy or azo type, can be poured into acontainer holding the solid oxidizing agent and thereby fill the voidspaces. Then upon standing at room temperature, or at slightly raisedtemperatures, the polymer or monomer will be converted to an infusiblestate with the oxidizing agent embedded therein.

However, whichever method of mixing is used, it is desirable to avoidthe generation of heat that will raise the temperature to the ignitionpoint of the oxidizing agent. Therefore, in some cases, it is desirableto precool the materials to be mixed or to provide means to withdraw theheat as it is generated.

While certain features of this invention have been described in detailwith respect to various embodiments thereof, it will, of course, beapparent that other modifications can be made within the spirit andscope of this invention, and it is not intended to limit the inventionto the exact details shown above except insofar as they are defined inthe following claims:

The invention claimed is:

1. A polymeric composition useful as a solid propellant fuel consistingessentially of 5-95 percent by weight of an oxidizer selected from theclass consisting of perchlorates, nitrates, persulfates and perboratesof sodium, potassium and ammonia, potassium chlorate, manganese dioxide,potassium iodate, potassium dichromate, chloric acid, perchloric acid,ammonium dichromate, ammonium iodate, barium chlorate, bariumperchlorate, barium permanganate, lithium perchlorate, lithiumdichromate, lithium permanganate, and aryl perchloryl compounds and -5percent by weight of a polymer having a plurality of repeating units inthe polymer molecule thereof having a formula wherein X is a groupselected from the class consisting of R and Y groups, R is a radicalselected from the class consisting of hydrogen and hydrocarbon radicalshaving no more than 24 carbon atoms therein, and Y is a polyvalentradical consisting of hydrocarbon and ether portions, said valenciesbeing connected to hydrocarbon portions thereof and having at least 2carbon atoms between said valency and each ether group therein.

2. A polymeric composition of claim 1 in which said polymer has aplurality of repeating units in the polymer molecule thereof having theformula 3. A polymeric composition of claim 1 in which said polymer hasa plurality of repeating units in the polymer molecule thereof havingthe formula 4. A polymeric composition of claim 1 in which said polymerhas a plurality of repeating units in the polymer molecule thereofhaving the formula 5. A polymeric composition of claim 1 in which saidpolymer has a plurality of repeating units in the polymer moleculethereof having the formula 6. A polymeric composition of claim 1 inwhich said polymer has a plurality of repeating units in the polymermolecule thereof having the formula 7. A polymeric composition of claim1 in which said polymer has a plurality of repeating units in thepolymer molecule thereof having the formula 8. A polymeric compositionof claim 1 in which said polymer has a plurality of repeating units inthe polymer molecule thereof having the formula 9. A polymericcomposition of clim 1 in which said polymer has a plurality of repeatingunits in the polymer molecule thereof having the formula 10. A polymericcomposition of claim 1 in which said oxidizer is potassium perchlorate.

11. A polymeric composition of claim 1 in which said oxidizer isammonium perchlorate.

12. A polymeric composition of claim 1 in which said oxidizer is an arylperchloryl compound.

17. A polymeric composition of claim 1 in which said oxidizer ispotassium perchlorate and said polymer has a plurality of repeatingunits in the polymer molecules thereof having the formula 18. Apolymeric composition of claim 1 in which said oxidizer is potassiumperchlorate and said polymer has a plurality of repeating units in thepolymer molecules thereof having the formula 20 19. A polymericcomposition of claim 1 in which said oxidizer is potassium perchlorateand said polymer has a plurality of repeating units in the polymermolecules thereof having the formula 1|tlC HuO 04H- CzHr 20. A polymericcomposition of-claim 1 in which said oxidizer is potassium perchlorateand said polymer has a plurality of repeating units in the polymermolecules thereof having the formula References Cited UNITED STATESPATENTS 2,844,551 7/1958 Orthner et al. 260-18 2,924,614 2/1960 Reuter260-448X VBENJAMIN R. PADGETI, Primary Examiner.

US. Cl. X.R. 149-1, 20; 60220

1. A POLYMERIC COMPOSITION USEFUL AS A SOLID PROPELLANT FUEL CONSISTINGESSENTIALLY OF 5-95 PERCENT BY WEIGHT OF AN OXIDIZER SELECTED FROM THECLASS CONSISTING OF PERCHLORATES, NITRATES, PERSULFATES AND PERBORATESOF SODIUM, POTASSIUM AND AMMONIA, POTASSIUM CHLORATE, MANGANESE DIOXIDE,POTASSIUM IODATE, POTASSIUM DICHROMATE, CHLORIC ACID, PERCHLORIC ACID,AMMONIUM DICHROMATE, AMMONIUM IODATE, BARIUM CHLORATE, BARIUMPERCHLORATE, BARIUM PERMANGANATE, LITHIUM PERCHLORATE, LITHIUMDICHROMATE, LITHIUM PERMANGANATE, AND ARYL PERCHLORYL COMPOUNDS AND 95-5PERCENT BY WEIGHT OF A POLYMER HAVING A PLURALITY OF REPEATING UNITS INTHE POLYMER MOLECULE THEREOF HAVING A FORMULA